Browsing by Author "Sari, E."
Now showing items 1-13 of 13
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Blue quantum electroabsorption modulators based on reversed quantum confined Stark effect with blueshift
Sari, E.; Nizamoglu, S.; Ozel, T.; Demir, Hilmi Volkan (AIP Publishing LLC, 2007-01-02)The authors present the design, growth, fabrication, experimental characterization, and theoretical analysis of blue quantum electroabsorption modulators that incorporate similar to 5 nm thick In0.35Ga0.65N/GaN quantum ... -
Comparative study of electroabsorption in InGaN/GaN quantum zigzag heterostructures with polarization-induced electric fields
Sari, E.; Ozel, T.; Koc, A.; Ju, J. W.; Ahn, H.-K.; Lee, I.-H.; Baek, J.-H.; Demir, Hilmi Volkan (AIP Publishing LLC, 2008-05-19)We present a comparative study on InGaN/GaN quantum zigzag structures embedded in p-i-n diode architecture that exhibit blue-shifting electroabsorption in the blue when an electric field is externally applied to compensate ... -
Dislocation density dependent electroabsorption in epitaxial lateral overgrown InGaN/GaN quantum structures
Sari, E.; Jang, L. W.; Baek, J. H.; Lee, I. H.; Sun, X. W.; Demir, Hilmi Volkan (Optical Society of America, 2013-01-14)We study electroabsorption (EA) behavior of InGaN/GaN quantum structures grown using epitaxial lateral overgrowth (ELOG) in correlation with their dislocation density levels and in comparison to steady state and time-resolved ... -
Electric field dependent radiative decay kinetics of polar InGaN/GaN quantum heterostructures at low fields
Sari, E.; Nizamoglu, S.; Lee, I. H.; Baek, J. H.; Demir, Hilmi Volkan (American Institute of Physics, 2009-05-29)Electric field dependent photoluminescence decay kinetics and its radiative component are studied in polar InGaN/GaN quantum heterostructures at low fields. Under externally applied electric field lower than polarization ... -
FRET-LEDs involving colloidal quantum dot nanophosphors
Nizamoğlu, S.; Sari, E.; Baek, J. H.; Lee, I. H.; Sun, X. W.; Demir, Hilmi Volkan (Webcom Communications, 2010)Semiconductor nanocrystal quantum dots (NQD) with their narrow and tuneable emission are promising candidates to serve as color convertors integrated on light-emitting diodes (LEDs). The use of nonradiative energy transfer, ... -
Green/yellow solid state lighting via radiative and nonradiative energy transfer involving colloidal semiconductor nanocrystals
Nizamoglu, S.; Sari, E.; Baek, J. H.; Lee, I. H; Demir, Hilmi Volkan (IEEE, 2009-08-05)LEDs made of In(x)Ga(1-x)N and (Al(x)Ga(1-x))(1-y)In(y)P suffer from significantly reduced quantum efficiency and luminous efficiency in the green/yellow spectral ranges. To address these problems, we present the design, ... -
Nonradiative resonance energy transfer directed from colloidal CdSe/ZnS quantum dots to epitaxial InGaN/GaN quantum wells for solar cells
Nizamoglu, S.; Sari, E.; Baek, J. H.; Lee, I. H.; Demir, Hilmi Volkan (Wiley, 2010-06-04)We report on Förster-type nonradiative resonance energy transfer (NRET) directed from colloidal quantum dots (QDs) to epitaxial quantum wells (QWs) with an efficiency of 69.6% at a rate of 1.527 ns-1 for potential application ... -
Opposite carrier dynamics and optical absorption characteristics under external electric field in nonpolar vs. polar InGaN/GaN based quantum heterostructures
Sari, E.; Nizamoglu, S.; Choi, J H.; Lee, S J.; Baik, K H.; Lee, I. H.; Baek, J. H.; Hwang, S M.; Demir, Hilmi Volkan (Optical Society of America, 2011)We report on the electric field dependent carrier dynamics and optical absorption in nonpolar a-plane GaN-based quantum heterostructures grown on r-plane sapphire, which are surprisingly observed to be opposite to those ... -
Spatially Selective Assembly of Quantum Dot Light Emitters in an LED Using Engineered Peptides
Demir, Hilmi Volkan; Seker, U. O. S.; Zengin, G.; Mutlugun, E.; Sari, E.; Tamerler, C.; Sarikaya, M. (American Chemical Society, 2011-02-23)Semiconductor nanocrystal quantum dots are utilized in numerous applications in nano- and biotechnology. In device applications, where several different material components are involved, quantum dots typically need to be ... -
Violet to deep-ultraviolet InGaN∕GaN and GaN∕AlGaN quantum structures for UV electroabsorption modulators
Ozel, T.; Sari, E.; Nizamoglu, S.; Demir, Hilmi Volkan (AIP Publishing LLC, 2007)In this paper, we present four GaN based polar quantum structures grown on c-plane embedded in p-i-n diode architecture as a part of high-speed electroabsorption modulators for use in optical communication (free-space ... -
White light generation by resonant nonradiative energy transfer from epitaxial InGaN/GaN quantum wells to colloidal CdSe/ZnS core/shell quantum dots
Nizamoglu, S.; Sari, E.; Baek, J.-H.; Lee, I.-H.; Demir, Hilmi Volkan (Institute of Physics Publishing Ltd., 2008)We propose and demonstrate white-light-generating nonradiative energy transfer (ET) from epitaxial quantum wells (QWs) to colloidal quantum dots (QDs) in their close proximity. This proof-of-concept hybrid color-converting ... -
White light generation tuned by dual hybridization of nanocrystals and conjugated polymers
Demir, Hilmi Volkan; Nizamoglu, S.; Ozel, T.; Mutlugun, E.; Huyal I.O.; Sari, E.; Holder, E.; Tian, N. (Institute of Physics Publishing Ltd., 2007)Dual hybridization of highly fluorescent conjugated polymers and highly luminescent nanocrystals (NCs) is developed and demonstrated in multiple combinations for controlled white light generation with high color rendering ... -
White light generation using CdSe/ZnS core–shell nanocrystals hybridized with InGaN/GaN light emitting diodes
Nizamoglu, S.; Ozel, T.; Sari, E.; Demir, Hilmi Volkan (Institute of Physics Publishing Ltd., 2007)We introduce white light generation using CdSe/ZnS core-shell nanocrystals of single, dual, triple and quadruple combinations hybridized with InGaN/GaN LEDs. Such hybridization of different nanocrystal combinations provides ...